This invention relates to an improved vehicle brake assembly, including both drum and disc type brakes, for use with non-driven vehicle wheels, and to a method of installing the assembly on an associated vehicle.
Generally, the brake assemblies for the non-driven wheels of a four wheel vehicle (e.g., the rear wheels on a front drive vehicle), incorporate a spindle and bearing means for rotatably supporting a hub and either a brake drum or disc. The brake, spindle, bearing means, and hub are secured to an unsprung vehicle component, such as one end of an axle tube, in various manners, depending upon the particular type of brake assembly.
One example of such a prior art drum brake assembly is illustrated in FIG. 1, and is indicated generally at 10. As shown therein, the drum brake assembly 10 includes a generally axially extending spindle or stub axle 12, a brake subassembly 13 including a backing plate 14, and a brake drum 16. The brake drum 16 includes an integrally cast hub 18, and a plurality of wheel mounting lugs 20 press-fit or otherwise secured in apertures formed in the brake drum 16.
The brake subassembly 13 further includes a pair of arcuate brake shoes, only one shoe 22 being shown, and other related brake components, such as disclosed in U.S. Pat. No. 5,070,968 to Evans, and herein incorporated by reference. The subassembly 13 is usually provided by the brake manufacturer. Typically, one of the brake components is a parking brake cable 24 extending from the backing plate 14 and operatively connected to actuate a parking and emergency brake mechanism (not shown). In some instances, the cable 24 is not part of the subassembly 13 but is connected to the parking and emergency brake mechanism after the brake assembly 10 has been assembled and secured to the vehicle.
In order to assemble and secure the brake assembly 10 to a vehicle component, such as an axle flange 26, the spindle 12 in inserted through a central opening formed in the backing plate 14 until a outboard side 28 of a vehicle mounting flange 30 of the spindle 12 engages an inboard side 32 of the backing plate 14. Next, a plurality of threaded hex head bolts 34 (only two of which are shown), are inserted through corresponding apertures formed in the backing plate 14 and the vehicle mounting flange 30 of the spindle 12. Nuts 36 are installed on the bolts 34 and tightened to secure the spindle 12 and the brake subassembly 13 to the axle flange 26.
Next, a grease seal 38 and an inner tapered roller bearing 40 are installed on the spindle 12. The brake drum 16 is placed over the backing plate 14 so that a threaded end 42 of the spindle 12 extends axially outwardly through the hub 18 of the brake drum 16. Next, an outer tapered roller bearing 44, a keyed washer 46, and a nut 48 are installed on the spindle 12. The nut 48 is tightened to predetermined specifications to properly load the bearings 40 and 44.
A nut retainer 50 is then inserted over the spindle end 40 and about the nut 48, and a cotter pin 52 is installed through a slot 54 formed in the nut 50, and through an aperture 56 formed in the spindle end 42. The nut retainer 50 and cotter pin 52 cooperate to prevent the nut 48 from loosening during operation of the vehicle. Finally, a generally dome-shaped protective cover 58 is press-fit onto the end of the hub 18 to prevent dirt and other debris from entering the brake assembly 10.
Another example of a prior art drum brake assembly is illustrated in FIG. 2, and is indicated generally at 60. As shown therein, the drum brake assembly 60 includes a brake subassembly 61 including a backing plate 62, a hub and bearing unit 64, and a brake drum 66. The hub and bearing unit 64 includes a vehicle mounting flange 68, a wheel mounting flange 70, and a spindle 72. A plurality of wheel mounting lugs 74 are press-fit into apertures formed in the wheel mounting flange 70, and the vehicle mounting flange 68 is provided with a plurality of threaded apertures (not shown). The brake subassembly 61 includes a pair of arcuate brake shoes, only one shoe 76 being shown, and other related brake components which are usually provided by the brake manufacturer.
In order to assemble and secure the brake assembly 60 to an axle flange 78 of a vehicle, the backing plate 62 and the hub and bearing unit 64 are positioned adjacent one another so that threaded apertures formed in the vehicle mounting flange 70 are aligned with apertures formed in the backing plate 62. Next, an inboard side 80 of the backing plate 62 is positioned adjacent the axle flange 78, and a plurality of hex head bolts 82 (only two of which are shown), are installed through apertures formed in the axle flange 78 and the backing plate 62, and are threadably received in the threaded apertures of the vehicle mounting flange 68. Tightening of the bolts 82 secures the brake subassembly 61 and the hub and bearing unit 64 to the axle flange 78.
The brake drum 66 is then placed over the brake subassembly 61 so that the lugs 74 extend through corresponding apertures formed in the drum 66. Finally, seating-lock type fasteners 84 are installed on the lugs 74 to secure the brake drum 66 to the backing plate 62, and therefore, to the axle flange 78. In some instances, the lugs 74 are press-fit into the drum 66, thus eliminating the need for the fasteners 84.
An example of a prior art disc brake assembly is illustrated in FIG. 3, and is indicated generally at 90. As shown therein, the disc brake assembly 90 includes a drum-in-hat parking brake. The brake assembly 90 further includes a spindle 92, a brake support casting 94, a hub 96, and a hat-shaped rotor 98. The brake support casting 92 includes a vehicle mounting flange 100 and a backing plate 102. A pair of arcuate brake shoes, only one shoe 104 being shown, and other related brake components, such as disclosed in U.S. Pat. No. 4,854,423 to Evans et al., and herein incorporated by reference, are usually provided by the brake manufacturer. The hub 96 includes a wheel mounting flange 104 having a plurality of wheel mounting lugs 106 press-fit into apertures formed therein.
In order to assemble and secure the brake assembly 90 to a fixed part of a vehicle, such as an axle flange 108, the spindle 92 is inserted through an aperture formed in the casting 94 until an outboard side 110 of a vehicle mounting flange 112 of the spindle 92 engages an inboard side 114 of the mounting flange 100. Next, a plurality of threaded hex head bolts 116 (only two of which are shown), are inserted through corresponding apertures formed in the flange 100 of the casting 94 and the flange 112 of the spindle 92. Nuts 118 are installed on the bolts 116 and tightened to secure the brake support casting 94 and the spindle 92 to the axle flange 110.
Next, an inner tapered roller bearing 120, the hub 96, an outer tapered roller bearing 122, a keyed washer 124, and a nut 126 are installed on the spindle 92 so that a threaded end 128 of the spindle 92 extends axially outwardly through the hub 96. The nut 126 is tightened to pre-load the bearings 120 and, 122. A nut retainer 130 is inserted over the spindle end 128 and about the nut 126, and a cotter pin 132 is installed through a slot 134 formed in the nut retainer 130, and through an aperture 136 formed in the spindle end 128. A generally dome-shaped protective cover 138 is press-fit onto the end of the hub 96.
The rotor 98 of the disc brake is then placed over the hub 96 so that the lugs 106 extend through corresponding apertures formed in the rotor 98. Finally, a disc brake caliper 140 is supported on the support casting 94 via a pair of guide rails, only one guide rail 142 being shown, and secured thereon by bolts 144.
In all of the above-described prior art brake assemblies, the individual brake components can be installed only after the spindle and the brake subassembly or the support casting are secured to the vehicle. Also, a shortage of any part of the brake assembly may affect the assembling and installing of the assembly on the vehicle, or may even require shutting down of the assembly line.